Have a spotter watch your bench press during a set of 3-5 reps, and then ask him to point out the point at which you seemed to be stuck. Usually, these weak points are chest liftoff, middle of range and top of motion lock.

If you show weakness at liftoff, you should start working on your form: make sure your shoulder blades are pulled back, giving you a platform to press from. For weakness at the middle of the range of motion, try doing some floor presses, meaning a dumbbell or barbell bench press while lying on the floor. For weakness at the lockout, work on your shoulders with a standing overhead barbell press.

3. Painful shoulders

Bench presses strain shoulders. You can alleviate the discomfort by stretching the pectoral minor muscles. Assume the position you would for a normal pec stretch. Perform a pressing motion with the arm, keeping the arm on the wall, until there is a 30-degree angle between your neck and arm. Lean away until you feel a stretch in your shoulder and where your pec meets your shoulder.